So that's why they moved up the Build conference. Forget windows 8 and how we messed that up, but look at how we make the best Home Video Game / Multimedia center / Consumer device. Develop for Xbox 720's will be the new Build theme.

Xbox 720 - not particularly original. I didn't like the original "Xbox 360" name anyway.

Nextbox - Internally at Microsoft we use "Next" as a placeholder name making this unlikely, plus it's going to get confusing when the 4th generation Xbox comes out.

Xbox {meaninglessName} - Nintendo did this with the "Wii U", Sony did it with the "PSP Vita", and we did it ourselves with Windows Vista and Windows XP. Word inside the company is that we, as an organization, have abandoned silly marketing gimmicks and are being more straightforward... if simple.

Xbox 3 - see above, it's simple and direct, however remember one reason we didn't name it the "Xbox 2" was in order to look better compared to the PlayStation 3 ("Xbox 2 or PlayStation 3 vs Xbox 360 or PlayStation 3").

Xbox S - Something that Apple and Samsung are up to (and car manufacturers) - take a brand and add "S" to the end - for sport, speed, or some other connotation you fancy. However we can't use this because we just called the revised Xbox 360 the "Xbox 360S".

Xbox - reboots are a thing nowadays - Batman, Superman, Wolfenstein, Tomb Raider - it stands to reason they'll just call it "Xbox" with no qualifier. If the rumors of total backwards-compatibility are true (because it's an x64 chip that'll be able to run the old Xbox's x86 code fine) then this works even better, because the new Xbox can play the old Xbox games without any issues, thus actually reducing customer confusion.

Xenon - this is the name of the chipset. It's possible, but unlikely they would use it as the name of the console.

Xbox 3 won't look good next to Playstation 4. 720 implies non-full HD. It's probably gonna be simply "Xbox", and lots of people on the internet will claim that they are totally confused about wether they're talking about the first Xbox or the new one but in reality everyone will know what they're referring to.

If they come up with some sort of touch based whatever for it, I'd say there's a good chance the Surface brand will be involved too.

My money's on "Xbox 720". It's obviously a major version up from Xbox 360 (compared with "XBOX S", "XBOX RED", "XBOX 3" etc), it keeps the Xbox brand and style of name (unlike "ZBOX"), it clearly doesn't move the product into a different sphere (like how Windows RT is a different "strand" of Windows to Windows 8) and it means that they don't have to have a disconnect between the pre-release press for Xbox 720 (which is largely positive) with the release press for it.

Note that they can't just go with "Xbox" - not only because that's the name of the original (i.e. pre-Xbox 360) console, but because it's a shorthand for the whole series of consoles. (When did you last "turn on your Xbox 360" versus "turn on your Xbox"? Do you say "Xbox 360! - my pins - hulu plus - queue" or do you say "Xbox! - my pins - hulu plus - queue"?) This is the same reason why the next version of Windows can't just be called "Windows", and why the next version of Office can't be called "Office".

They also clearly own the trademark for "Xbox" already as well as all of the online support (such as xbox.com), so last minute ill-advised changes like the Metro --> Modern fiasco (due to a trademark issue in Germany) isn't going to happen.